U.S. patent number 5,599,306 [Application Number 08/536,555] was granted by the patent office on 1997-02-04 for method and apparatus for providing external perfusion lumens on balloon catheters.
This patent grant is currently assigned to LocalMed, Inc.. Invention is credited to Paul Alba, Jordan Bajor, Aaron V. Kaplan, Enrique J. Klein.
United States Patent |
5,599,306 |
Klein , et al. |
February 4, 1997 |
Method and apparatus for providing external perfusion lumens on
balloon catheters
Abstract
A catheter sleeve includes a radially expansible distal region
having a plurality of axial blood perfusion lumens or channels
formed thereon. The catheter sleeve may be introduced over a
conventional angioplasty balloon catheter with the expansible
region lying over the balloon. When the balloon of the angioplasty
catheter is expanded, the perfusion lumens will provide a flow path
for blood around the expanded balloon. Optionally, the catheter
sleeve may further include drug infusion lumens over the radially
expansible region. In this way, drugs can be delivered over
prolonged periods while the underlying angioplasty balloon is
inflated and blood flows through the lumens or channels to perfuse
the distal myocardium.
Inventors: |
Klein; Enrique J. (Los Altos,
CA), Bajor; Jordan (Palo Alto, CA), Alba; Paul (San
Jose, CA), Kaplan; Aaron V. (Los Altos, CA) |
Assignee: |
LocalMed, Inc. (Palo Alto,
CA)
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Family
ID: |
26915943 |
Appl.
No.: |
08/536,555 |
Filed: |
September 29, 1995 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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461222 |
Jun 5, 1995 |
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221613 |
Apr 1, 1994 |
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Current U.S.
Class: |
604/103.01;
604/103.07; 604/509; 604/523 |
Current CPC
Class: |
A61M
25/104 (20130101); A61M 2025/0183 (20130101); A61M
2025/1004 (20130101); A61M 2025/1072 (20130101); A61M
2025/1079 (20130101); A61M 2025/1081 (20130101); A61M
2025/1095 (20130101); A61M 25/0023 (20130101); A61M
25/1002 (20130101); A61M 2025/0025 (20130101); A61M
2025/0063 (20130101) |
Current International
Class: |
A61M
29/02 (20060101); A61M 25/10 (20060101); A61M
25/00 (20060101); A61M 025/00 () |
Field of
Search: |
;604/96,21,104,97,103,52,53,107,49,28,266,264 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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WO92/11890 |
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Jul 1992 |
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WO |
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WO92/11895 |
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Jul 1992 |
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WO |
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WO93/21985 |
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Nov 1993 |
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WO |
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9321985 |
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Nov 1993 |
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WO |
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WO94/11053 |
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May 1994 |
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WO |
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WO94/11048 |
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May 1994 |
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WO |
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WO95/03082 |
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Feb 1995 |
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WO |
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WO95/03081 |
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Feb 1995 |
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WO |
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Other References
Bom, N. et al. "Early and recent intraluminal ultrasound devices,"
1989, Internal Journal of Cardiac Imaging 4:79-88. .
Advanced Cardiovascular Systems, Inc., Temecula, California, "ACS
Rx Perfusion.TM. Coronary Dilatation Catheter," 1990, (Product
Brochure) pp. 1-23. .
Hong, M. K. et al. "A New PTCA Balloon Catheter With Intramural
Channels For Local Delivery of Drugs at Low Pressure," 1992,
Supplement to Circulation, Abstracts From the 65th Scientific
Sessions, vol. 86, No. 4, #1514. .
EndoSonics, Pleasanton, California, "The Cathscanner.RTM.
Intracoronary Imaging System," 1992, (Product Brochure). .
Scimed.RTM., Maple Grove, Minnesota, "Dispatch.TM.," 1994, (Product
Brochure). .
ACS Rx Perfusion.TM. Coronary Dilatation Catheter, from Advanced
Cardiovascular Systems, Inc., Temecula, CA, package insert
copyright 1990. .
Product literature from Scimed Life Systems, Inc., May 1994,
Dispatch.TM...
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Primary Examiner: Green; Randall L.
Assistant Examiner: Van Over; Perry E.
Attorney, Agent or Firm: Townsend and Townsend and Crew
LLP
Parent Case Text
This is a Continuation of application Ser. No. 08/461,222, filed
Jun. 5, 1995, now abandoned which is a Continuation of application
Ser. No. 08/221,613, filed Apr. 1, 1994, now abandoned.
Claims
What is claimed is:
1. A catheter sleeve comprising:
a flexible tubular body having a proximal end, a distal end, and a
central lumen therethrough, wherein at least a portion of the
tubular body is radially expansible as a result of a radial
expansion force applied in the central lumen within said portion;
and
at least one perfusion lumen disposed over said radially expansible
portion of the tubular body, wherein said lumen has a plurality of
axially spaced-apart ports distributed substantially uniformly over
its length which permit blood flow through the lumen.
2. A catheter sleeve comprising:
a flexible tubular body having a proximal end, a distal end, and a
central lumen therethrough, wherein at least a portion of the
tubular body is radially expansible as a result of a radial
expansion force applied in the central lumen within said portion;
and
one or more channels disposed over said radially expansible portion
of the tubular body, wherein the channels define flow paths between
the tubular body and a surrounding blood vessel wall.
3. A catheter sleeve as in claim 1 or 2, wherein the tubular body
is radially expansible over a length in the range from about 1.5 cm
to 5 cm near the distal end.
4. A catheter sleeve as in claim 3, wherein the tubular body has a
diameter which is radially expansible to a diameter of 5 mm.
5. A catheter sleeve as in claim 1, further comprising structure in
at least one of the lumens to reinforce said lumen to prevent
compression or collapse of the lumen.
6. A catheter sleeve as in claim 3, wherein the reinforcing
structure comprises a helical wire supporting the interior of the
lumen.
7. A catheter sleeve as in claim 1, further comprising additional
lumens having means for infusing therapeutic agents
therethrough.
8. A catheter sleeve as in claim 7, wherein the lumens having
therapeutic agent infusing means are paired with lumens having
perfusion flow means with a common wall therebetween, wherein the
tubular body is slit between adjacent pairs.
9. A catheter sleeve as in claim 8, wherein the tubular body is
slit between adjacent lumen pairs along a length in the range from
1.5 cm to 5 cm near the distal end.
10. A catheter sleeve as in claim 1, including at least two
perfusin lumens wherein the tubular body is slit between the lumens
to enhance radial expansibility.
11. A catheter sleeve as in claim 1, wherein substantially the
entire length of the tubular body is radially expansible.
12. A catheter sleeve as in claim 8 wherein a proximal portion of
the catheter body is pleated, rolled, or slit to facilitate passage
of a large diameter portion of a balloon catheter through the
central lumen.
13. A catheter sleeve as in claim 1, wherein a proximal portion of
the flexible tubular body has side ports to enhance the flow of
perfusion liquid through a guiding catheter when the catheter
sleeve is in place therein.
14. A catheter sleeve as in claim 1, wherein the
perfusion-flow-establishing means comprise helically arranged flow
paths.
15. A catheter sleeve as in claim 14, further comprising at least
one helical drug infusion tube formed over the radially expansible
portion of the tubular body.
16. A catheter sleeve as in claim 14, wherein the tubular body is
helically split between said flow paths.
17. A catheter sleeve as in claim 1, wherein the
perfusion-flow-establishing means comprises a pair of adjacent
lumens formed on one side of the tubular body, wherein the lumens
are separated by a common septum and are split from the remainder
of the tubular body to permit radial expansion.
18. A catheter sleeve as in claim 17, further comprising a
radiopaque marker attached to the septum.
19. A catheter sleeve as in claim 18, wherein the radiopaque marker
comprises a pair of plates secured to each other on opposite sides
of the septum.
20. A catheter sleeve as in claim 17, further comprising a
plurality of axial spacers on a side of the tubular body opposite
to the pair of adjacent lumens.
21. A catheter sleeve as in claim 20, wherein the spacers have
solid cross-section.
22. A catheter sleeve as in claim 20, wherein the spacers are
inflatable.
23. A catheter sleeve as in claim 1, further comprising a rod
having a diameter less than that of the tubular body attached to a
proximal end of the tubular body.
24. A catheter sleeve as in claim 17, wherein axially spaced-apart
hinges are formed in the tubular body along the adjacent pair of
lumens to enhance flexibility.
25. A catheter sleeve as in claim 1, wherein the
perfusion-flow-establishing means comprises a triple lumen blood
perfusion tube formed over the tubular body, wherein a center lumen
includes perfusion ports and the two flanking lumens are closed to
permit inflation to selectively reinforce the center lumen.
26. A catheter sleeve as in claim 25, wherein the blood perfusion
tube is arranged helically over the tubular body, further
comprising a helical drug infusion tube disposed opposite to the
blood perfusion tube over the tubular body, wherein the tubular
body is split between the blood perfusion tube and the drug
infusion tube to permit radial expansion.
27. A catheter sleeve as in claim 1, wherein the lumen has a
plurality of axially spaced-apart ports which permit blood flow
through the lumen.
28. A catheter sleeve as in claim 27, further comprising structure
in at least one of the lumens to reinforce said lumen to prevent
compression or collapse of the lumen.
29. A method for perfusing blood past a treatment site within a
blood vessel, said method comprising:
positioning a sleeve having a central lumen at said treatment site,
said sleeve defining at least one flow path thereover, wherein said
flow path provides both axial flow and radially inward and outward
flow over substantially its entire length; and
applying a radial force within the central lumen to expand the
sleeve within the treatment site while blood flows past the
expanded sleeve through said at least one flow path and radially in
and out of the flow path over substantially the entire expanded
length of the sleeve.
30. A method as in claim 29, further comprising positioning a
dilatation balloon catheter within a distal end of the sleeve and
inflating said balloon to radially expand said sleeve.
31. A method as in claim 30, wherein the balloon is inflated to a
pressure in the range from 0.5 atm to 16 atm.
32. A method as in claim 29, further comprising delivering a
therapeutic agent to said treatment site through said sleeve while
said sleeve is radially expanded.
33. A method as in claim 29, wherein the sleeve is positioned in
the blood vessel so that blood flowing past the expanded sleeve
enters a branch blood vessel.
34. A method as in claim 29, wherein the radially expanding step
comprises inflating a balloon within the sleeve at low pressure for
a prolonged period to preserve the initial inflation perimeter of
the balloon.
35. A method for delivering a therapeutic agent to a treatment site
on an interior wall of a blood vessel, said method comprising:
positioning a sleeve at said treatment site, said sleeve having a
plurality of axial flow paths thereover;
radially expanding the sleeve to contact an exterior surface
thereof against the interior wall of the blood vessel; and
infusing the therapeutic agent through at least some of the flow
paths to the blood vessel wall, wherein others of said flow paths
establish blood perfusion past the radially expanded sleeve.
36. A method as in claim 35, further comprising positioning a
balloon catheter within a distal end of the sleeve and inflating
said balloon to radially expand said sleeve.
37. A method as in claim 36, wherein the balloon is inflated to a
pressure in the range from 0.5 atm to 16 atm.
38. A method as in claim 35, wherein the sleeve is positioned at
the treatment site after an angioplasty procedure has been
performed at the same site.
39. An improved method for treating a target location within a
blood vessel, said method being of the type wherein a balloon is
expanded against an interior wall of the blood vessel, wherein the
improvement comprises providing radially open perfusion flow paths
over an outer surface of the balloon, whereby blood flow is
established through said perfusion paths.
40. An improved method as in claim 39, further comprising providing
drug infusion lumens disposed over an outside surface of the
balloon and infusing a therapeutic agent therethrough to the target
location.
41. An improved method as in claim 39, wherein the perfusion flow
paths are provided by positioning a catheter sleeve over the
balloon, wherein the catheter sleeve is radially expansible and
includes said perfusion flow paths thereon.
42. An improved method as in claim 39, wherein the balloon is
expanded by inflating to a pressure in the range from 0.5 atm to 16
atm.
43. A catheter sleeve comprising:
a flexible tubular body having a proximal end, a distal end, and a
central lumen therethrough, wherein at least a portion of the
tubular body is axially split to permit radial expansion as a
result of a radial expansion force applied in the central lumen
within said portion; and
means over a radially expansible portion of the tubular body near
the distal end for establishing blood perfusion flow.
44. A catheter sleeve as in claim 43, wherein the
perfusion-flow-establishing means comprises at least one perfusion
lumen disposed over said radially expansible portion of the tubular
body, wherein said lumen has a plurality of axially spaced-apart
ports which permit blood flow through the lumen.
45. A catheter sleeve as in claim 43, further comprising structure
in at least one of the lumens to reinforce said lumen to prevent
compression or collapse of the lumen.
46. A catheter sleeve as in claim 45, wherein reinforcing structure
comprising a helical wire supporting interior of the lumen.
47. A catheter sleeve as in claim 44, including at least two
prefusion lumens wherein the tubular body is slit between the
lumens to enhance radial expansibility.
48. A catheter sleeve as in claim 43, wherein the
perfusion-flow-establishing means comprises one or more channels
disposed over said radially expansible portion of the tubular body,
wherein the channels define flow paths between the tubular body and
a surrounding blood vessel wall.
49. A catheter sleeve as in claim 43 or 48, wherein the tubular
body is radially expansible over a length in the range from about
1.5 cm to 5 cm near the distal end.
50. A catheter sleeve as in claim 49, wherein the tubular body has
a diameter which is radially expansible to a diameter of 5 mm.
51. A catheter sleeve as in claim 43, wherein a proximal portion of
the flexible tubular body has side ports to enhance the flow of
perfusion liquid through a guiding catheter when the catheter
sleeve is in place therein.
52. A catheter sleeve as in claim 43, wherein the
perfusion-flow-establishing means comprise helically arranged flow
paths.
53. A catheter sleeve as in claim 52, further comprising at least
one helical drug infusion tube formed over the radially expansible
portion of the tubular body.
54. A catheter sleeve as in claim 52, wherein the tubular body is
helically split between said flow paths.
55. A catheter sleeve as in claim 43, wherein the
perfusion-flow-establishing means comprises a pair of adjacent
lumens formed on one side of the tubular body, wherein the lumens
are separated by a common septum and are split from the remainder
of the tubular body to permit radial expansion.
56. A catheter sleeve as in claim 43, further comprising a rod
having a diameter less than that of the tubular body attached to a
proximal end of the tubular body.
57. A catheter sleeve as in claim 43, wherein the
perfusion-flow-establishing means comprises a triple lumen blood
perfusion tube formed over the tubular body, wherein a center lumen
includes perfusion ports and the two flanking lumens are closed to
permit inflation to selectively reinforce the center lumen.
58. A catheter sleeve as in claim 43, further comprising additional
lumens having means for infusing therapeutic agents
therethrough.
59. A catheter sleeve as in claim 58, wherein the lumens having
therapeutic agent infusing means are paired with lumens having
perfusion flow means with a common wall therebetween, wherein the
tubular body is slit between adjacent pairs.
60. A catheter sleeve as in claim 59, wherein the tubular body is
slit between adjacent lumen pairs along a length in the range from
1.5 cm to 5 cm near the distal end.
61. A method for perfusing blood past a treatment site within a
blood vessel, said method comprising:
positioning a sleeve having a central lumen at said treatment site,
said sleeve defining at least one flow path thereover and being
axially split in the region of the flow path; and
applying a radial force within the central lumen to expand the
sleeve within the treatment site while blood flows past the
expanded sleeve through said at least one flow path, wherein radial
expansion causes circumferential separation of the axial
split(s).
62. A method as in claim 61, further comprising positioning a
dilatation balloon catheter within a distal end of the sleeve and
inflating said balloon to radially expand said sleeve.
63. A method as in claim 61, wherein the balloon is inflated to a
pressure in the range from 0.5 atm to 16 atm.
64. A method as in claim 61, further comprising delivering a
therapeutic agent to said treatment site through said sleeve while
said sleeve is radially expanded.
65. A method as in claim 61, wherein the sleeve is positioned in
the blood vessel so that blood flowing past the expanded sleeve
enters a branch blood vessel.
66. A method as in claim 61, wherein the radially expanding step
comprises inflating a balloon within the sleeve at low pressure for
a prolonged period to preserve the initial inflation perimeter of
the balloon.
67. A catheter sleeve comprising:
a flexible tubular body having a proximal end, a distal end, and a
central lumen therethrough, wherein at least a portion of the
tubular body is radially expansible as a result of a radial
expansion force applied in the central lumen within said portion;
and
at least one perfusion lumen integrally formed as a single
extrusion as part of the tubular body near the distal end for
establishing blood perfusion flow.
68. A catheter sleeve as in claim 67, wherein the tubular body is
radially expansible over a length in the range from about 1.5 cm to
5 cm near the distal end.
69. A catheter sleeve as in claim 68, wherein the tubular body has
a diameter which is radially expansible to a diameter of 5 mm.
70. A catheter sleeve as in claim 66, including at least two
integrally formed perfusion lumens, wherein the tubular body is
slit between the lumens to enhance radial expansibility.
71. A catheter sleeve as in claim 67, further comprising additional
integrally formed lumens having means for infusing therapeutic
agents therethrough.
72. A method for perfusing blood past a treatment site within a
blood vessel, said method comprising:
positioning a sleeve having a central lumen at said treatment site,
said sleeve including at least one perfusion lumen integrally
formed as a single extrusion thereover; and
applying a radial force within the central lumen to expand the
sleeve within the treatment site while blood flows past the
expanded sleeve through said at least one perfusion lumen.
73. A method as in claim 72, wherein the radially expanding step
comprises inflating a balloon within the sleeve at low pressure for
a prolonged period to preserve the initial inflation perimeter of
the balloon.
74. A method as in claim 72, further comprising positioning a
dilatation balloon catheter within a distal end of the sleeve and
inflating said balloon to radially expand said sleeve.
75. A method as in claim 74, wherein the balloon is inflated to a
pressure in the range from 0.5 atm to 16 atm.
76. A method as in claim 72, further comprising delivering a
therapeutic agent to said treatment site through said sleeve while
said sleeve is radially expanded.
77. A method as in claim 72, wherein the sleeve is positioned in
the blood vessel so that blood flowing past the expanded sleeve
enters a branch blood vessel.
78. A method for perfusing blood past a treatment site within a
blood vessel, said method comprising:
inflating a balloon catheter to dilate a blood vessel treatment
site to an initial inflation perimeter;
deflating the balloon;
positioning a sleeve having a central lumen over the deflated
balloon at said treatment site, said sleeve defining at least one
flow path thereover; and
reinflating the balloon within the sleeve at low pressure in the
range from 0.5 atm to 5 atm for a prolonged period to preserve the
initial inflation perimeter of the balloon.
79. A catheter sleeve comprising:
a flexible tubular body having a proximal end, a distal end, and a
central lumen therethrough, wherein at least a portion of the
tubular body is radially expansible as a result of a radial
expansion force applied in the central lumen within said
portion;
means over a radially expansible portion of the tubular body near
the distal end for establishing blood perfusion flow; and
means over the radially expansible portion of the tubular body near
the distal end for infusing therapeutic agents.
80. A catheter sleeve as in claim 79, wherein the
perfusion-flow-establishing means comprises at least one lumen
disposed over said radially expansible portion of the tubular body,
wherein said lumen has a plurality of axially spaced-apart ports
which permit blood flow through the lumen.
81. A catheter sleeve as in claim 80, wherein the tubular body is
radially expansible over a length in the range from about 1.5 cm to
5 cm near the distal end.
82. A catheter sleeve as in claim 81, wherein the tubular body has
a diameter which is radially expansible to a diameter of 5 mm.
83. A catheter sleeve as in claim 79, wherein the therapeutic agent
infusing means comprises at least one infusion lumen having means
for releasing the agent therethrough.
84. A catheter sleeve as in claim 83, wherein the lumens having
therapeutic agent infusing means are paired with lumens having
perfusion flow means with a common wall therebetween, wherein the
tubular body is slit between adjacent pairs.
85. A catheter sleeve as in claim 84, wherein the tubular body is
slit between adjacent lumen pairs along a length in the range from
1.5 cm to 5 cm near the distal end.
Description
CROSS-REFERENCE TO RELATED APPLICATION
This application is related to application Ser. No. 08/222,143,
filed on the same day as the present application, the full
disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to intravascular dilatation
devices, and more specifically to intravascular catheters to
provide blood flow during dilatation and other therapeutic
procedures.
In percutaneous transluminal angioplasty procedures, a catheter
having an expansible distal end, usually in the form of a balloon,
is positioned in a lumen of a blood vessel with the distal end
disposed within a stenotic atherosclerotic region of the vessel.
The expansible end is then expanded to dilate the vessel and
restore adequate blood flow through the diseased region. During
dilatation blood flow is interrupted, limiting inflation time to
between 0.5 and 3 minutes.
While angioplasty has gained wide acceptance, it continues to be
limited by two major problems, abrupt closure and restenosis.
Abrupt closure refers to the acute occlusion of a vessel
immediately after or within the initial hours following the
dilatation procedure. This complication, occurring in approximately
one in twenty cases, frequently results in myocardial infarction
and death if blood flow is not quickly restored. At present,
arterial dissections, one of the causes of abrupt closure, are
treated by prolonged balloon inflations lasting more than 5
minutes. Special angioplasty balloon catheters which allow for
perfusion through the dilatation catheter during inflation are
required for this purpose. Restenosis refers to the re-narrowing of
an artery after an initially successful angioplasty. Restenosis
usually occurs within the initial six months after angioplasty and
afflicts approximately one in three cases. Therefore, approximately
one in three patients will require additional revascularization
procedures. Many different strategies have been tried
unsuccessfully to reduce the restenosis rate, including mechanical
(e.g., prolonged balloon inflations, atherectomy, laser and
stenting) and pharmacologic (e.g., calcium antagonists, ace
inhibitors, fish oils, steroids and anti-metabolic) approaches. One
promising new strategy is to delivery agent directly to the
arterial wall at the site of angioplasty. Several devices have been
developed to deliver agent locally into the arterial wall. Similar
to angioplasty balloon catheters, balloon deployed drug delivery
catheters interrupt blood flow, limiting the time available to
deliver agent.
Thus, it would be desirable to provide perfusion capabilities to
angioplasty catheters and to agent delivery devices for the
treatment of abrupt closure and restenosis and other purposes.
2. Description of the Background Art
A drug delivery catheter having an internal blood perfusion lumen
and external drug delivery balloon is described in WO93/21985.
Vascular drug delivery catheters are described in U.S. Pat. Nos.
5,087,244; 4,994,033; 5,021,044; and 5,112,305. U.S. Pat. Nos.
5,087,247; 4,892,519; and 4,790,315, describe angioplasty balloon
catheters having integral blood perfusion capability. U.S. Pat. No.
4,661,094, describes a blood perfusion catheter intended primarily
to provide blood flow through an occluded blood vessel. U.S. Pat.
Nos. 5,163,921 and 5,180,364, describe guiding catheters having
perfusion flow ports at their distal ends. Angioplasty catheters
having integral blood perfusion capability are commercially
available, e.g., under the tradename ACS Rx Perfusion.TM. Coronary
Dilatation Catheter, from Advanced Cardiovascular Systems, Inc.,
Temecula, Calif., as described in a package insert copyright
1990.
SUMMARY OF THE INVENTION
According to the present invention, methods and apparatus are
provided for establishing perfusion blood flow during balloon
angioplasty, vascular drug delivery, and related procedures. In a
preferred embodiment, the method and apparatus provide perfusion
blood flow during an intravascular drug infusion procedure where a
plurality of drug infusion lumens and blood perfusion lumens are
radially expanded and engaged against a treatment site using a
conventional balloon angioplasty catheter. In this way, prolonged
drug infusion can be performed while maintaining adequate blood
perfusion to tissue distal to the site of the procedure.
Apparatus according to the present invention comprise a catheter
sleeve including a flexible tubular body. The flexible tubular body
has a proximal end, a distal end, and a central lumen for slidably
receiving a balloon angioplasty catheter therethrough. A portion of
the flexible tubular body is radially expansible, usually
comprising a plurality of axial slits formed near the distal end of
the catheter body. In this way, an angioplasty catheter having its
balloon disposed within the axially slit portion of the catheter
will be able to significantly expand the catheter sleeve. By
providing blood flow perfusion means, typically in the form of
axial external flow paths comprising channels and/or tubular
members having open lumens, over the radially expansible portion,
blood perfusion flow can be established over the exterior surface
of an angioplasty balloon during drug delivery procedures,
prolonged balloon expansion to treat arterial dissection, and the
like. In contrast with previous balloon perfusion catheter designs,
where flow is established internally through an interior lumen of
the catheter, the present invention establishes flow over the
outside wall of the balloon, thus permitting use with even the
smallest diameter (lowest profile) balloon angioplasty catheters.
Additionally, such external lumens or channels permit perfusion to
branch vessels which is not possible with catheters having internal
perfusion lumens.
Preferably, additional axial lumens will be provided on the sleeve
for infusing drugs therethrough. In this way, prolonged drug
infusion therapy can be effected using a conventional balloon
angioplasty catheter for radial expansion of the catheter sleeve.
While axial channels or lumens will generally be preferred for both
the blood perfusion function and the drug infusion function, it
will be appreciated that other means external to the catheter
sleeve could also be provided for establishing the necessary flow
paths. For example, helical channels or lumens could be formed
over, or annular lumens or compartments could be formed within, the
radially expansible wall of the catheter sleeve in order to provide
the desired flow paths.
Methods according to the present invention include both balloon
expansion and drug delivery procedures to treat arterial dissection
and for other purposes. For expansion (i.e., tacking up
dissections) only, the catheter sleeve is used as described above
and need only include blood perfusion lumens. A conventional
balloon angioplasty catheter is used within the catheter sleeve to
provide the support necessary for the treatment of arterial
dissection. Balloon inflation pressures will typically be less than
those associated with balloon dilatation, usually from 0.5 atm to 5
atm, but may be up to 16 atm. For drug delivery, the catheter
sleeve will include both the blood perfusion flow paths and one or
more lumens for drug delivery. A balloon angioplasty catheter can
be used within the catheter sleeve to expand the blood perfusion
flow paths and the drug delivery lumens, usually at pressures
sufficient to maintain contact between the drug infusion lumens and
the interior wall of the blood vessel.
In addition to its primary usefulness in providing perfusion during
prolonged expansion and/or drug delivery protocols, the catheter
sleeves of the present invention can be advantageously used during
conventional and complex balloon angioplasty procedures. By placing
the expansible portion of the sleeve directly over the dilatation
balloon following the primary angioplasty procedure, prolonged
inflations can be maintained with the balloon inflated at low
pressure to preserve the initial inflation perimeter of the
balloon. Alternatively, use of higher inflation pressures with the
sleeve catheter can increase the effective size of the balloon. The
use of the sleeve to provide a larger dilatation perimeter can
eliminate the need to exchange balloon catheters to increase size,
as often required for tacking up dissections.
In a preferred catheter sleeve intended for drug infusion and
simultaneous blood perfusion, infusion lumens and blood perfusion
lumens are formed in pairs on the radially expansible portion of
the catheter sleeve with a common wall therebetween. Axial slits
are provided between adjacent pairs of drug infusion/blood
perfusion lumens, and the lumen pairs may then be radially expanded
using a conventional angioplasty balloon catheter as described
above. Such pairing of the drug infusion lumens and blood perfusion
lumens is advantageous since it minimizes the number of walls and
amount of material necessary to form the catheter sleeve,
permitting fabrication of a catheter sleeve having a minimum
profile or diameter.
A further understanding of the nature and advantages of the
invention will become apparent by reference to the remaining
portions of the specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a blood perfusion catheter sleeve
constructed in accordance with the principles of the present
invention.
FIG. 2 is a cross-sectional view of the catheter sleeve of FIG. 1,
taken along line 2--2.
FIG. 3 is a cross-sectional view of the catheter sleeve of FIG. 1,
taken along line 3--3.
FIG. 4 is a cross-sectional view of the radially expansible portion
of the catheter of FIG. 1, shown in its expanded configuration with
a dilatation balloon therein.
FIG. 5 illustrates the catheter sleeve of FIG. 1 in use with a
balloon dilatation catheter in treating a region of stenosis within
a blood vessel.
FIGS. 5A and 5B illustrate an alternate embodiment of a catheter
sleeve constructed in accordance with the principles of the present
invention.
FIG. 6 is a perspective view of a preferred catheter sleeve
constructed in accordance with the principles of the present
invention and combining both blood perfusion and drug infusion
capabilities.
FIG. 7 is a cross-sectional view of the catheter sleeve of FIG. 6,
taken along line 7--7 of FIG. 6.
FIG. 8 is a cross-sectional view of the catheter sleeve of FIG. 6,
taken along line 8--8 of FIG. 6.
FIGS. 9A-9D illustrate an exemplary method of the present invention
utilizing the catheter sleeve of FIG. 6 in combination with a
balloon angioplasty catheter for performing an angioplasty
procedure followed by drug infusion.
FIG. 10 is a cross-sectional view taken along line 10--10 of FIG.
9D.
FIGS. 11-15 illustrate optional modifications of the catheter of
FIGS. 1 and 6, where the shaft of the catheter has a reduced
diameter.
FIG. 16 is a cross-sectional view of a blood perfusion catheter
sleeve similar to FIG. 1, having a single pair of adjacent
perfusion lumens on one side of its distal end.
FIG. 17 is a cross-sectional view of the catheter sleeve of FIG. 16
shown on an inflated balloon in its expanded configuration.
FIG. 18 is a partial, perspective view of the catheter of FIG. 16,
showing an optional hinge structure.
FIGS. 18A-18C illustrate a blood perfusion catheter similar to that
illustrated in FIGS. 16-18 and having spacer bars on a side
opposite to the pair of perfusion lumens.
FIG. 18D illustrates a blood perfusion catheter sleeve similar to
that illustrated in FIGS. 16-18, where the proximal portion of the
sleeve is replaced with a connecting rod or tube.
FIG. 19 is a perspective view with portions broken away of the
distal end of a blood perfusion catheter having helical perfusion
and drug infusion lumens, where the perfusion lumens may be
hydraulically stiffened.
FIGS. 20-22 are cross-sectional views of the perfusion lumen of the
catheter of FIG. 19.
FIG. 23 illustrates an additional embodiment of a blood perfusion
catheter sleeve according to the present invention having a pair of
helically arranged perfusion lumens and a helical expansion
slot.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
Catheter sleeves according to the present invention will comprise a
flexible tubular body which may be formed from a single extrusion
or from multiple extrusions which are joined either in tandem or in
parallel, as described in more detail hereinbelow. The overall
dimensions of the catheter body will depend on use, with the length
varying widely, typically being between about 40 cm and 150 cm,
usually being between about 40 cm and 120 cm for peripheral
catheters and being between about 110 cm and 150 cm for coronary
catheters. The diameter of the flexible tubular body will be
selected to be compatible with a dilatation catheter with which it
is to be used. Most importantly, the flexible tubular body of the
present invention will have a central lumen having a diameter which
is sufficient to accommodate passage of the uninflated balloon of
the angioplasty catheter when passing therethrough.
As described in more detail hereinbelow, at least a portion of the
catheter body will be radially expansible to permit expansion of
the dilatation balloon therein. In addition, other portions of the
flexible tubular body may be radially expansible to facilitate
passage of the balloon in its uninflated configuration
therethrough. The inner diameter of the flexible tubular body will
typically be in the range from about 1 mm to 3 mm. More typically
being in the range from about 1.3 mm to 2.0 mm.
The flexible tubular body may be composed of a wide variety of
biologically compatible material, typically being formed from
natural or synthetic polymers, such as polyvinylchloride,
polyurethanes, polyesters, polyethylenes, polytetrafluoroethylene
(PTFE's), and the like, with elastomeric portions of the body being
formed from natural rubber, silicone rubber, and the like.
Optionally, the catheter body may be formed as a composite having
one or more reinforcement layers incorporated within its
elastomeric body in order to enhance strength, flexibility, and
toughness, particularly within the portion which is not radially
expansible. Exemplary reinforcement layers include wire mesh, metal
braid, and the like. The flexible tubular body will normally be
formed by conventional extrusion of a desired polymeric material,
forming the central lumen as well as one or more additional lumens,
as described in more detail hereinbelow. The various lumen
diameters can be modified if desired by heat expansion and
shrinkage using conventional techniques. Specific techniques for
forming the vascular catheters of the present invention are well
described in the patent and medical literature.
At least a portion of the catheter body will be radially
expansible. By "radially expansible," it is meant that the catheter
body will be capable of expanding in an outward, radial direction
when an expansion force is applied in the central lumen, e.g., by
expansion of a dilatation balloon of a conventional angioplasty
catheter. Usually, the inside diameter of the radially expansible
portion of the flexible tubular body will initially be in the range
from 1 mm to 3 mm and will be expansible up to 4 mm or more,
consistent with commercially available balloon dilatation
catheters. Such radial expansibility may be provided by forming the
catheter body wholly or partly from an elastomeric material, e.g.,
silicone rubber. Alternatively, and preferably, such expansibility
will be provided by forming a plurality of axial slits in the
catheter body, resulting in segments of the catheter body which
will separate upon radial expansion. Other methods for forming
radially expansible tubular bodies include involuted folds,
overlapping C-shaped sections, accordion folds, and the like.
Frequently, it may be desirable to form the catheter body into
distinct axial segments having the same or different mechanical
properties and which may be composed of different materials. For
example, it may be desirable to form a proximal segment of the
catheter body from a flexible, but non-radially expansible,
material and structure. A radially expansible distal segment can
then be joined to the distal end of the proximal segment.
Alternatively, it may be desirable to provide a different number of
lumens in the distal region of the catheter sleeve than in the
proximal region. This can be achieved using different extrusions of
the same or different materials. An example of such a structure is
described in connection with FIGS. 6-10.
In a particular embodiment descirbed in connection with FIG. 18D
below, a proximal portion of the catheter sleeve body is formed by
a narrow diameter rod or tube which will be disposed in parallel
with the dilatation catheter within the guiding catheter. The rod
or tube will typically have a diameter in the range from 0.0005 mm
to 0.001 mm, usually being composed of a flexible metal, such as
stainless steel. The attaching tube or rod will provide the ability
to axially advance or retract the catheter sleeve over the balloon
catheter, with the necessary perfusion lumens being formed on the
distal sleeve portion only. By utilizing hypotube as the proximal
portion of the catheter sleeve body, a lumen can be provided for
drug delivery or other purposes.
One or more flow paths will be provided over the radially
expansible portion of the flexible tubular body in order to
establish perfusion flow therethrough when the catheter sleeve is
placed in a blood vessel and the expansible portion expanded by a
dilatation balloon, as described in more detail hereinafter.
Conveniently, the flow paths are provided by one or more axial
lumens disposed on or in the radial expansible portion of the
tubular wall, preferably being formed as integral or discrete
perfusion tubes over the tubular wall or as open flow channels over
the tubular wall. In the case of perfusion tubes, one or more flow
ports will be provided at a proximal end of said tubes in order to
permit the inflow of blood to the axial lumen within the tube, and
one or more ports will be provided near the distal end of the
perfusion tube in order to provide for blood outflow. Preferably,
ports will also be distributed along the entire length of the
perfusion tubes in order to allow perfusion to arterial branch
vessels, as described in connection with FIG. 5, below. In some
cases, it may be necessary that the axial lumens be reinforced in
order to prevent lumen compression or even collapse. Blood flowing
within the perfusion lumens will be at physiologic pressure, i.e.,
about 80 mmHg which is approximately equal to 0.1 atm. The
perfusion tubes, however, will be exposed to elevated external
pressures resulting from the balloon inflation which urges the
perfusion tubes against the radially stretched inner vessel wall.
Sufficient reinforcement may be necessary in order to prevent
compression or collapse under such elevated pressures. Suitable
reinforcement structures will provide sufficient hoop strength
while being sufficiently flexible in the transverse and
longitudinal direction so that they permit easy placement of the
catheter sleeve within a blood vessel. Suitable structures include
flexible mechanical scaffolding, usually in the form of helices,
spirals, and the like, as well as hydraulic scaffolding where a
pressurized fluid is introduced into additional closed lumens
within the catheter sleeve body.
In a preferred aspect of the present invention, additional flow
paths will be provided on the radially expansible region of the
flexible catheter body in order to permit drug infusion
therethrough. Such drug infusion flow paths will typically be in
the form of axial lumens, more typically being in the form of axial
tubes formed over the catheter body. In the case of drug infusion,
it is necessary that these axial lumens and/or tubes be connected
to a proximal end of the tubular body so that the desired drug can
be fed to the lumens. This may be accomplished with lumens formed
along the entire length of the flexible tubular body, or
alternatively with a single lumen over the proximal portion of the
tubular body connected to two or more drug infusion tubes via a
manifold.
The perfusion flow paths will typically extend over a length of the
flexible tubular body which is substantially greater than that
which is radially expanded. The radially expansible portion need
only be about 1.5 cm to 5 cm in length to accommodate most
conventional angioplasty balloons. The perfusion flow paths may be
much longer, typically being at least 10 cm, usually being from 12
cm to 30 cm. Most or all of the additional length will usually
(although not necessarily) be on the proximal side of the radially
expansible segment so that there is ample opportunity for blood to
enter the flow paths upstream of the balloon when expanded.
Referring now to FIG. 1, a first embodiment of a catheter sleeve 10
intended for providing blood perfusion flow in connection with
arterial dissection treatment following balloon angioplasty is
described. The catheter sleeve 10 comprises flexible tubular body
12 having a proximal end 14 and a distal end 16. The flexible
tubular body includes a proximal portion 18 which is in the form of
a tube having a single, central lumen 20. The flexible tubular body
12 further includes a radially expansible distal portion 22 which
comprises four discrete blood perfusion lumens 24, as best observed
in FIGS. 2 and 3. Each perfusion lumen 24 includes a plurality of
ports 26 spaced apart axially along its length. In this way, blood
perfusion can be established through the lumens 24 by entering
through the proximal-most ports 26 and flowing out through the
distal-most ports 28, as illustrated by arrows in FIG. 5.
Referring to FIGS. 4 and 5, expansion of the radially expansible
distal portion of catheter sleeve 10 will be described. A
conventional balloon angioplasty catheter 40 having balloon 42
(shown in its expanded condition in FIG. 4), is disposed within the
expansible distal portion 22 of the sleeve. The balloon 42 is
expanded, forcing perfusion lumens 24 radially outward and into
contact with the interior of the blood vessel, typically in a
region of stenosis S which has previously been dilated and which is
now being treated to inhibit abrupt vessel closure resulting from
arterial dissection. Thus, contact with the blood vessel wall can
be maintained for an extended period of time without occlusion of
the blood primary vessel P or branch vessel B. In a preferred
aspect of the present invention, the treating physician can assure
that perfusion is directed to the branch vessel by introducing
contrast medium and repositioning the catheter/sleeve combination
until one or more side ports 26 are aligned with the branch vessel
and flow is observed.
As best seen in FIG. 5, only the distal most portion of the
perfusion tubes 24 is radially expanded by the dilatation balloon
42. Often, the entire distal portion 22 of the flexible tubular
body 12 will be axially slit between adjacent perfusion lumens 24
over the entire length of said lumens, e.g., 10 cm to 30 cm, but
the portion which is actually radially expanded will be determined
by the length of the dilatation balloon which is inflated therein,
typically from 1.5 cm to 5 cm. The extra length of the perfusion
lumens will enhance perfusion flow as described above.
FIGS. 5A and 5B illustrate an alternate embodiment of a catheter
sleeve 500 constructed in accordance with the principles of the
present invention. The catheter sleeve 500 comprises a flexible
tubular body 502 having a proximal end (not illustrated) and a
distal end 506. The flexible tubular body 502 includes a proximal
portion 508 which is in the form of a tube having a central lumen
510. The body 502 further includes a radially expansible distal
portion 512 (typically formed as a separate extrusion and
subsequently joined to the proximal portion 508) having four
perfusion channels 514 formed over its periphery. The distal
portion 512 will be axially split, typically along a pair of
opposed axial lines 516, allowing the resulting halves to be
expanded by an internal dilatation balloon 520, as illustrated in
FIG. 5B, where the cross-section of the distal portion 512 is shown
in an expanded configuration in full line and a non-expanded
configuration in broken line. A soft distal tip 517 is secured to
the distal end of the distal portion 512, and the proximal end of
the distal section is secured to the proximal portion 508. Thus,
both ends of the distal section are constrained as the middle
portion is expanded by a balloon, as shown in FIG. 5B.
The use of open channels 514 in place of closed lumens having a
plurality of perfusion ports is advantageous since blood can enter
and/or exit the channels at any point along the length where the
channel is exposed to blood flow. Such increased access facilitates
aligning the catheter sleeve with branch blood vessels. An
additional advantage of the embodiment of FIGS. 5A and 5B is an
increase in the flow area available for perfusion in comparison to
designs with fully enclosed lumens. Such increase results from
elimination of the outer wall of an enclosed lumen, which decreases
the total amount of sleeve material which occupies the interior of
the blood vessel. Such a decrease in occupied area leaves more room
available for perfusion.
Referring now to FIGS. 6, 7, and 8, a preferred catheter sleeve 100
constructed in accordance with the principles of the present
invention will be described. Catheter sleeve 100 includes both
blood perfusion lumens and drug infusion lumens on a radially
expansible portion thereof. In particular, catheter sleeve 100
includes a flexible tubular body 102 which extends from a proximal
end 104 to a distal end 106 thereof. A soft, atraumatic tip 108 is
provided at the distal end, and a proximal housing 110 is provided
at the proximal end. Housing 110 includes a first access port 112
for introducing a conventional balloon angioplasty catheter
therethrough and a second access port 114 for delivering a drug to
be infused through the drug infusion lumens of the catheter
sleeve.
The flexible catheter body 102 comprises a single extrusion having
a central lumen 120 and three peripheral drug supply lumens 122.
The drug supply lumens 122 are connected with the drug infusion
port 114 in order to supply drugs to the distal end of the catheter
sleeve 100.
A blood perfusion portion 126 of the catheter sleeve is provided at
the distal end of the flexible tube body 102. The blood perfusion
portion 126 will be formed as a separate extrusion and will be
attached to the distal end of the proximal portion of the body,
typically by thermal fusion, adhesives, ultrasonic welding, or the
like. The blood perfusion portion 126 includes both drug infusion
lumens 130 (FIG. 8) and blood perfusion lumens 132. The drug
infusion lumens 130 include a plurality of infusion ports 134, and
the blood perfusion lumens 132 include a plurality of proximal
inlet ports 136 (FIG. 6) and intermediate and distal outlet ports
138. A radially expansible region within the blood perfusion
portion 126 further includes a central lumen 140 which receives the
balloon of a balloon dilatation catheter, as described in more
detail hereinafter. The radially expansible region is slit along
lines 142 to permit radial expansion, as best observed in FIG. 8.
The slits 142 may extend along the entire length of the blood
perfusion portion 126, but more typically will be disposed only in
the distal 1.5 cm to 5.0 cm, usually 2.0 cm to 3.0 cm, where the
balloon will be disposed. Conveniently, radiopaque markers 127 may
be provided in the catheter body to delineate the radially
expansible region and facilitate placement of the sleeve over a
dilatation balloon catheter.
The blood perfusion portion 126 will have a length in the range
from about 5 cm to 25 cm, preferably being from about 7.5 cm to 15
cm, with the expansible portion being selected to be compatible
with conventional balloon angioplasty catheters, e.g. less than 5
cm, usually in the range from 2 to 3 cm. Conventional dilatation
balloons are available commercially from vendors such as Advanced
Cardiovascular Systems, Inc., Temecula, Calif. By providing three
drug infusion lumens 130 and three perfusion lumens 132, and
splitting the radially expansible portion between adjacent
drug/perfusion lumen pairs, as illustrated in FIG. 8, each drug
infusion/blood perfusion lumen pair will have a common wall
therebetween. Reliance on a common wall increases the
cross-sectional area available for infusion/perfusion lumens in
that region. FIG. 8 also discloses reinforcement members 144
disposed with each of the blood perfusion lumens 132. Conveniently,
the reinforcement member will be in the form of a flat metal helix
which extends the entire length of the lumen 132, where perfusion
ports 136 are aligned with spaces between adjacent turns of the
helix.
In the preferred embodiment of FIG. 6, blood perfusion lumens 132
are sealed at each end. At the proximal end, the blood perfusion
lumens 132 are sealed by pinching off an otherwise open end of the
lumen. The lumens are sealed at the distal end by the flexible tip
108. The drug infusion lumens 130 are aligned coaxially with and
adjoined to the lumens 122 on the proximal portion of the flexible
catheter body 102 Additionally, the blood perfusion lumens 132 are
shown to have a greater area than the infusion lumens 130
Typically, the combined areas of the three perfusion lumens 132
will be at least 0.5 mm.sup.2 preferably being from 10 mm.sup.2 to
1.3 mm.sup.2, or greater, in order to provide a sufficient
perfusion flow rate The combined area of the drug infusion lumens
is less critical, typically being from 0.05 mm.sup.2 to 0.2
mm.sup.2.
Referring now to FIGS. 9A-9D, use of the catheter sleeve 100 for
delivering drugs after a conventional angioplasty procedure will be
described An angioplasty catheter C is introduced so that a balloon
B lies within a region of stenosis S in a blood vessel BV. The
catheter sleeve 100 may be introduced simultaneously with the
balloon catheter C, typically being disposed over a proximal
portion of the catheter as illustrated in FIG. 9A. In either case,
the catheter C or the catheter/catheter sleeve combination, will be
introduced over a guidewire under fluoroscopic observation using
conventional techniques.
Once in place, the balloon B may be inflated to distend the vessel
in the region of stenosis S, as illustrated in FIG. 9B. The
catheter sleeve 100 will usually be disposed proximal to the
balloon in order to be ready for use after the initial angioplasty
procedure is completed.
After completing the angioplasty procedure, the balloon B is
deflated, and the catheter sleeve 100 advanced distally or the
balloon B is drawn proximally so that the radially expansible
portion 126 lies over the angioplasty balloon. After properly
positioning the balloon B and the catheter sleeve 100, as
illustrated in FIG. 9C, the balloon B is inflated within the
radially expansible portion 126 of the sleeve so that the drug
infusion lumens 130 and blood flow perfusion lumens 132 are brought
into contact with the inner wall of the blood vessel, as
illustrated in FIG. 9D. Once in the radially expanded state, the
blood flow perfusion lumens 132 provide a perfusion flow path, with
blood entering through ports 136 and leaving through ports 138, as
indicated by the arrows in FIG. 9D. At the same time, the drug
infusion lumens 130 permit drug delivery through the infusion ports
134, as best illustrated in FIG. 10, which is a cross-sectional
view taken along line 10--10 of FIG. 9D. FIG. 10 also illustrates
(in broken line) the outline of the radially expansible region 126
of catheter sleeve 100, in the non-expanded configuration.
The catheter sleeve 100 may be further modified to provide
additional capabilities and advantages, as will now be described.
For example, the proximal region (shaft) of the catheter body may
include a plurality of apertures 150 along its entire length (FIG.
6) in order to enhance the flow of a fluid, such as contrast media,
through a guiding catheter when the catheter sleeve is present in a
guiding catheter. The catheter sleeve of the present invention will
necessarily have a larger diameter or "profile" than the balloon
angioplasty catheter over which it is introduced. Thus, a greater
portion of the cross-sectional area of the internal lumen of a
guiding catheter will be occupied when the catheter sleeve is in
use. While this results in a loss of luminal area for delivering
contrast media and the like through the guiding catheter, such loss
of area can be ameliorated by providing the ports 150 in the
catheter body 102. Ports 150 allow fluid access to the annular
space between the angioplasty balloon catheter and the inner
luminal wall of the catheter sleeve, thus providing up to 15% or
more cross-sectional area for the delivery of fluids
therethrough.
Further modifications of the proximal region of the flexible
catheter body 102 are illustrated in FIGS. 11-14. The catheter body
102 needs to be sufficiently large in order to accommodate the
dilatation balloon and other protuberances on the balloon
angioplasty catheter which is to be introduced therethrough. By
providing a catheter tube body 102' which is resiliently
expansible, the outer profile of the catheter within the guiding
catheter may be kept small while still permitting entry of the
dilatation catheter. For example, as illustrated in FIGS. 11 and
12, the catheter tube body 102' may include one or more axial
pleats 160 along its length so that the effective diameter can
increase as a larger device (or portion of a device), such as
folded balloon B shown in broken line in FIG. 12, is introduced
therethrough. After the larger device or device portion has passed,
the catheter body 102' will return to its reduced diameter, as
illustrated in FIG. 11, thus leaving a larger area in the guiding
catheter which is available for the passage of contrast media.
Such expansibility on the proximal portion of the catheter shaft
may also be provided by including an involuted fold 200 in catheter
body 102" as illustrated in FIGS. 13 and 14. The web between
adjacent perfusion lumens may be thinned in the region where the
fold is to be provided, typically being half as thick as the web in
the other regions of the catheter body 102', and the web may be
folded over as illustrated in FIG. 13. As a balloon angioplasty
catheter or other device is passed through the lumen of the
catheter body 102", the fold 200 will unfurl to allow passage for
example of an enlarged distal end of the catheter, as illustrated
in FIG. 14. After the enlarged portion has passed, the catheter
body 102" will return to its original folded configuration, as
illustrated in FIG. 13.
An alternative reduced-diameter configuration of the catheter body
of FIG. 1 is illustrated in FIG. 15. A modified proximal portion
18" of the catheter body is axially split along its length in order
to allow passage of an enlarged distal portion of a catheter to
pass through its lumen. Optionally, the catheter body may be
reinforced with wire or other resilient elements to maintain the
profile as illustrated in FIG. 15.
The ability to introduce an angioplasty catheter into a catheter
sleeve having a relatively small clearance between its inner
luminal wall and the outer surface of the folded balloon or other
protuberances on the angioplasty catheter shaft, is influenced by
the closeness of the fit, friction between the contacting
materials, the presence of fluid between the catheter and the
catheter sleeve, and the length of engagement between the catheter
and the catheter sleeve.
The catheter sleeve 100 may be further modified to provide a larger
clearance for the angioplasty balloon catheter over the
proximal-most approximately three-quarters of the catheter sleeve,
thus reducing the length of engagement over the tightest
one-quarter of the catheter sleeve length and enhancing the ability
to introduce an angioplasty catheter therethrough. The incremental
loss in luminal area between the inner luminal wall of the guiding
catheter and the out surface of the catheter sleeve can then be
compensated for by addition of ports 150, as described earlier.
A distal portion of a perfusion catheter sleeve 300 is illustrated
in FIGS. 16-18. The catheter sleeve 300 includes a primary lumen
302 and a pair of adjacent perfusion lumens 304 having a plurality
of perfusion ports 306 spaced-apart thereon. The web of the
catheter body will be split along lines 310 to permit radially
expansion by internal inflation of an angioplasty balloon B, as
illustrated in FIG. 17. A septum 312 separates the perfusion lumens
304 and acts to reinforce the perfusion lumens to inhibit
compression and collapse of the lumens during use. A radiopaque
marker 314 is attached to the septum 312, typically by stapling to
the septum or by folding one or more tabs 316 through a slot and
over on the opposed face of the septum.
The catheter sleeve 300 has particular advantages. First, it can
accommodate a wide range of artery sizes, typically, from 2 mm to 4
mm and larger. Second, the profile of adjacent lumens 304 is such
that their available crosssectional areas increase as the sleeve is
radially expanded. By comparing FIGS. 16 and 17, it can be seen
that the portion of the catheter body web underlying the perfusion
lumens flattens as the underlying balloon B is expanded. This
results in the lumens opening up to provide an increased area for
blood perfusion flow.
The catheter sleeve 300 may be modified to enhance flexibility by
providing thinned hinge regions or joints 320, as illustrated in
FIG. 18. Such articulations allow the catheter body to bend and
flex more readily while maintaining the stiffness of the luminal
segments and without reducing the available luminal cross-sectional
area.
A further modification of the design of the catheter 300 is
illustrated in FIGS. 18A-18C. A modified catheter 400 includes a
primary lumen 402 and a pair of adjacent perfusion lumens 404
having a plurality of perfusion ports 406 spaced-apart thereon. A
septum 412 separates the perfusion lumens 404 and acts to reinforce
the perfusion lumens to inhibit compression and collapse during
use. A radiopaque marker 414 and an attachment plate 416 are
attached to the septum 312 using staples, rivets, or equivalent
fasteners. As described thus far, the construction of catheter 400
is similar to that of catheter 300.
Catheter 400 further includes a plurality of spacer bars 420 formed
axially over the expansible region of the catheter and separated by
splits 422 formed in the web of the catheter. Thus, when the
catheter 400 is expanded over an angioplasty balloon B (FIG. 18C),
each of the spacer bars 420 will separate from the others and from
the perfusion channels 404. The spacer bars 420 will form axial
perfusion gaps 430 between the exterior surface of balloon B and
interior wall of the artery A.
As illustrated in FIGS. 18A and 18C, the spacer bars have solid
cross-sections which can readily be formed in the extrusion of the
catheter body. It would also be possible to form miniature balloon
spacers 440, as illustrated in FIG. 18B. The spacers 440 would each
have a lumen 442 which would be connectable to a pressurized
inflation source. The spacers 440 could thus be deployed and
stiffened by internal pressurization, as shown in broken line in
FIG. 18B. Use of balloon spacers can be advantageous since the
profile of the catheter will be reduced during introduction and
withdrawal when the balloons need not be inflated.
Still a further modification of the design of the catheter 300 is
illustrated in FIG. 18D. Catheter 450 includes a distal sleeve
portion 452 having a cross-section identical to that of catheter
300. A primary lumen 454 and a pair of adjacent perfusion lumens
456 extend over the distal sleeve portion 452 which has a length in
the range from 5 cm to 50 cm, usually from 5 cm to 25 cm. A single
slit 457 in the primary lumen 454 allows for expansion of the
distal sleeve in the region of the dilatation balloon. A connecting
rod 458 is attached to the proximal end of the sleeve portion 452
and permits axial reciprocation of the sleeve relative to the
balloon dilatation catheter B over which it has been introduced.
The balloon dilatation catheter B is received within the primary
lumen 454, as described with the previous embodiments, but the
connecting rod 458 extends proximally from the sleeve portion 452
in parallel with the proximal shaft of the balloon dilatation
catheter. It will be appreciated that substitution of such a
connecting rod may be used in any of the preceding embodiments
which do not provide for drug infusion. For embodiments that
provide for drug infusion, it will be possible to substitute a
narrow diameter tube (e.g. hypotube) of comparable diameter which
can provide a drug supply lumen. The connecting rod 458 will
usually be a flexible metal rod, typically stainless steel, having
a diameter in the range from 0.3 mm to 0.8 mm.
The use of a small diameter connecting rod 458, or equivalent
hypotube structure, is advantageous in that available lumen area
within the guiding catheter for introduction of contrast media and
other purposes is increased. Thus, the embodiment of FIG. 18D can
be viewed as an alternative to the embodiments of FIGS. 11-15.
A distal portion of a catheter sleeve 500 having a hydraulically
stiffened perfusion lumen structure 502 is illustrated in FIGS.
19-22. The catheter sleeve 500 can also include one or more drug
infusion tubes 504 over its exterior surface (with one being
illustrated in FIG. 19), although the drug infusion tube(s) would
not be necessary in a catheter sleeve intended for perfusion only.
The distal portion of the catheter sleeve 500 will be helically
split along line 506 in order to allow radial expansion with an
internal balloon catheter, as generally described for previous
embodiments.
The first unique feature of the catheter sleeve 500 is the
triple-lumen structure 502, illustrated in FIGS. 19-22. The
perfusion lumen structure 502 includes a primary perfusion lumen
510 flanked by a pair of adjacent distally closed lumens 512 which
may be inflated and stiffened with an incompressible fluid, e.g.
contrast media or saline, in order to support the primary lumen
510. An expansible distal portion of the primary lumen 510 includes
perfusion ports 514 in order to provide blood perfusion, as
generally described with the prior embodiments.
The expansible distal portion 501 and a transitional region 503 to
the non-expansible proximal portion 505 of the catheter sleeve 500
are illustrated in FIG. 19. It will be appreciated that the primary
lumen 510 need not be provided on the proximal portion of the
catheter sleeve 500. It will, however, be necessary to provide
extensions of the inflatable lumens 512. Conveniently, the
inflation lumens 512 may be formed on the proximal portions of the
catheter 500 as illustrated in FIGS. 19 and 20. An extrusion with a
wall thickness of 0.08 to 0.2 mm is initially formed including all
three lumens 510 and 512 of the triple-lumen structure 502. The top
511 of the primary lumen 510 (shown in broken line in FIG. 20) can
then be removed, leaving a two-lumen structure. As part of the
manufacturing process the distal portion of the triple-lumen 502
structure can then be expanded by internal pressurization under
heat to form the enlarged structure of FIG. 21. Such heat expansion
techniques are well known in the field of catheter construction,
e.g. in the fabrication of non-compliant dilatation balloons. The
distal ends of the inflation lumens 512 can then be sealed.
Perfusion ports 514 may then be formed in the primary perfusion
lumen 510. The resulting triple-lumen structure 502 will thus have
a very thin and flexible wall with a thickness from 0.025 mm to
0.04 mm when not inflated. Advantageously, the thin-walled
structure will be collapsible so that the triple-lumen structure
can be folded as illustrated in FIG. 22. When inflated with a
suitable pressure, typically from 1 atm to 10 atm, the perfusion
lumen structure 502 will unfurl to provide an expanded blood
perfusion path.
The use of a helical perfusion lumen structure 502 and a helical
drug infusion tube 504 is advantageous since they facilitate
aligning perfusion holes with side branches in the arterial
vasculature and distributing drugs more evenly around an arterial
lumen. The catheters of the present invention will usually be
non-reinforced, making it difficult to rotate their distal ends by
turning the proximal end. Thus, for catheter sleeves having axially
aligned perfusion tube structures, such as illustrated in FIG. 1,
it may sometimes be difficult to rotate the distal end of the
catheter in order to perfuse a particular arterial side branch. By
providing helical perfusion tubes having a fairly tight helical
pitch, it will be appreciated that perfusion ports 514 may be
provided in substantially all radial directions. Thus, by axially
translating the catheter sleeve 500 within an artery, it will
usually be possible to locate at least one perfusion port 514 which
is properly radially aligned with a given arterial side branch.
An additional embodiment of the distal end of a catheter sleeve 600
is illustrated in FIG. 23. The catheter sleeve 600 includes a
single helical pair of perfusion tubes 602 and a slot 604. Such a
helical structure has generally the same advantages as described
above in connection with catheter sleeve 500. The slot 604 will
typically have a width in the range from about 0.1 mm to 0.5 mm,
and will provide a high degree of flexibility and expansibility in
the distal region of the catheter sleeve 600. The central lumen 610
of the catheter sleeve 600 may extend the entire length of the
catheter sleeve, or the catheter sleeve may be attached to a
connecting rod similar to rod 454 illustrated in FIG. 18D. The use
of helical perfusion tubes (and optionally drug infusion tubes) is
particularly preferred with embodiments employing connecting rods
since the rotational alignment of the distal ends of such
structures is very difficult.
The catheter sleeves of the present invention are suitable for
delivery of a variety of therapeutic agents including
pharmaceuticals, proteins, peptides, nucleotides, carbohydrates,
polysaccharides, mucopolysaccharides, simple sugars,
glycosaminoglycans, steroids, and the like. The drugs will be
liquid soluble or dispersable in a suitable liquid carrier in order
to be delivered through the drug infusion lumens of the catheter
sleeve. The drugs may be present in a variety of formulations,
including dissolved or dispersed, as just described, or present in
a variety of carriers, such as microcarriers, liposomes, and the
like. The catheter sleeves of the present invention may also be
suitable for delivering other biological substances, such as
genetic material and suitable vectors to effect genetic
transformation. The catheter sleeves will preferably be used for
delivering drugs having direct benefit to the cardiovascular
system, including antithrombotics, antiplatelets, antimetabolics,
growth factor inhibitors, anticoagulants, antimitotics,
antibiotics, and the like.
Although the foregoing invention has been described in some detail
by way of illustration and example, for purposes of clarity of
understanding, it will be obvious that certain changes and
modifications may be practiced within the scope of the appended
claims.
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